Welcome to Allpar. If the 'ck eng' light came on and the battery hasn't been disconnected, there should be a fault code stored in the PCM. This code may help in diagnosis.
http://www.allpar.com/fix/codes.html
The ATF cooler lines run to the radiator and the cooler may be plugged (with clutch debris?) and the pressure line may be leaking. It is generally better to replace the radiator rather than try to unclog the cooler, if this is what has happened.
You can run the lines to an external aftermarket cooler, but then you lose the fluid warming advantage of the radiator in cold weather. ATF at 10 degF pours like syrup. ATF+4 is a synthetic and although probably not mandatory for your 46RE, it offers superior flexibility with temperature and wear characteristics. The price of ATF+4 is a little more, but it has come down in recent years.
What was the condition of the old fluid? Was there debris in the bottom of the pan and the filter dirty?
I hope that it isn't too late for the transmission, but it sounds like it took a beating and if the rest of the truck is in good shape, it may be worth a rebuild, reman or good used unit.
http://www.allpar.com/fix/codes.html
The ATF cooler lines run to the radiator and the cooler may be plugged (with clutch debris?) and the pressure line may be leaking. It is generally better to replace the radiator rather than try to unclog the cooler, if this is what has happened.
You can run the lines to an external aftermarket cooler, but then you lose the fluid warming advantage of the radiator in cold weather. ATF at 10 degF pours like syrup. ATF+4 is a synthetic and although probably not mandatory for your 46RE, it offers superior flexibility with temperature and wear characteristics. The price of ATF+4 is a little more, but it has come down in recent years.
What was the condition of the old fluid? Was there debris in the bottom of the pan and the filter dirty?
I hope that it isn't too late for the transmission, but it sounds like it took a beating and if the rest of the truck is in good shape, it may be worth a rebuild, reman or good used unit.